The present invention generally relates to a manipulator, and more particularly to a fuzzy control method and apparatus for a manipulator, and a manipulator system using the method and apparatus.
In a conventional manipulator control method, each articulation angle is obtained through geometric coordinate transformation on the basis of a given position/orientation of the manipulator terminal or tip, as described in Chapter III of "Robot Manipulator" by R. P. Pole, translated Kunio Yoshikawa, published in September, 1984 by Corona Shuppan K. K. If the dynamic characteristics, e.g. vibrations of a manipulator are also to be controlled, a model is formulated and a complicated formula is solved, as described in Japanese Patent Laid-open Publication JP-A-62-235602.
The above conventional technique requires a voluminous calculation for the determination of command values to articulations of a manipulator, resulting in a problem of a long sampling time starting from measuring a position with a sensor to fetching the calculation results. Another significant subject is to process a so-called singular point which has a value 0 at the denominator of a formula. Further since a manipulator system is expressed by formulas, these formulas are required to change with environmental conditions and control conditions.